Retail investors accustomed to buying personal finance books online can now purchase mutual funds from Amazon.com. The Seattle-based e-tailer, which sells everything from electronics to pet food, has inked a non-exclusive deal with Fidelity Investments to sponsor a new financial-services “store” that will give Web surfers a chance to buy funds, stocks, retirement plans and college savings plans through links on the Amazon home page. So, the next time you're ordering Snausages online, you can also stock up on mutual funds. One has to wonder what's next? Selling put options on eBay?